/*
 * Copyright (C) 2013 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.jay.angla.ble;

import android.annotation.SuppressLint;
import android.app.Service;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothGatt;
import android.bluetooth.BluetoothGattCallback;
import android.bluetooth.BluetoothGattCharacteristic;
import android.bluetooth.BluetoothGattDescriptor;
import android.bluetooth.BluetoothGattService;
import android.bluetooth.BluetoothManager;
import android.bluetooth.BluetoothProfile;
import android.content.Context;
import android.content.Intent;
import android.os.Binder;
import android.os.IBinder;
import android.text.format.Time;
import android.util.Log;

import java.io.UnsupportedEncodingException;
import java.sql.Date;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Formatter;
import java.util.HashMap;
import java.util.List;
import java.util.UUID;

/**
 * Service for managing connection and data communication with a GATT server
 * hosted on a given Bluetooth LE device.
 */
@SuppressLint("NewApi")
public class BluetoothLeService extends Service {
	private final static String TAG = BluetoothLeService.class.getSimpleName();

	private BluetoothManager mBluetoothManager;
	private BluetoothAdapter mBluetoothAdapter;
	private String mBluetoothDeviceAddress;
	private BluetoothGatt mBluetoothGatt;
	private int mConnectionState = STATE_DISCONNECTED;

	private static final int STATE_DISCONNECTED = 0;
	private static final int STATE_CONNECTING = 1;
	private static final int STATE_CONNECTED = 2;

	public final static String ACTION_GATT_CONNECTED = "com.jay.compass.ble.ACTION_GATT_CONNECTED";
	public final static String ACTION_GATT_DISCONNECTED = "com.jay.compass.ble.ACTION_GATT_DISCONNECTED";
	public final static String ACTION_GATT_SERVICES_DISCOVERED = "com.jay.compass.ble.ACTION_GATT_SERVICES_DISCOVERED";
	public final static String ACTION_DATA_AVAILABLE = "com.jay.compass.ble.ACTION_DATA_AVAILABLE";
	public final static String ACTION_DEVICE_FIND = "com.jay.compass.ble.ACTION_DEVICE_FIND";
	public final static String EXTRA_DATA = "com.jay.compass.ble.EXTRA_DATA";
	public final static String ACTION_GATT_TOAST = "com.jay.compass.ble.ACTION_GATT_TOAST";
	public final static String ACTION_GATT_SEND_SUCCESS = "com.jay.compass.ble.ACTION_GATT_SEND_SUCCESS";

	public final static UUID UUID_SERIAL_TRANSFER = UUID
			.fromString(SampleGattAttributes.SERIAL_TRANSFER);

	private boolean writeDone = true;

	@SuppressLint("NewApi")
	private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
		@Override
		public void onConnectionStateChange(BluetoothGatt gatt, int status,
				int newState) {
			String intentAction;
			if (newState == BluetoothProfile.STATE_CONNECTED) {
				intentAction = ACTION_GATT_CONNECTED;
				mConnectionState = STATE_CONNECTED;
				broadcastUpdate(intentAction);
				Log.i(TAG, "Connected to GATT server.");
				// Attempts to discover services after successful connection.
				Log.i(TAG, "Attempting to start service discovery:"
						+ mBluetoothGatt.discoverServices());

			} else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
				intentAction = ACTION_GATT_DISCONNECTED;
				mConnectionState = STATE_DISCONNECTED;
				System.out.println("Disconnected from GATT server.");
				broadcastUpdate(intentAction);
			}
		}

		@Override
		public void onServicesDiscovered(BluetoothGatt gatt, int status) {
			if (status == BluetoothGatt.GATT_SUCCESS) {
				broadcastUpdate(ACTION_GATT_SERVICES_DISCOVERED);
				discoverGattServices(getSupportedGattServices());
			} else {
				Log.w(TAG, "onServicesDiscovered received: " + status);
			}
		}

		@Override
		public void onCharacteristicRead(BluetoothGatt gatt,
				BluetoothGattCharacteristic characteristic, int status) {
			if (status == BluetoothGatt.GATT_SUCCESS) {
				broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
			}
		}

		public void onCharacteristicWrite(BluetoothGatt gatt,
				BluetoothGattCharacteristic characteristic, int status) {
			if (status == BluetoothGatt.GATT_SUCCESS) {
				writeDone = true;
			}
		};

		@Override
		public void onCharacteristicChanged(BluetoothGatt gatt,
				BluetoothGattCharacteristic characteristic) {
			broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
		}
	};

	private void broadcastUpdate(final String action) {
		final Intent intent = new Intent(action);
		sendBroadcast(intent);
	}

	private void broadcastUpdate(final String action,
			final BluetoothGattCharacteristic characteristic) {
		final Intent intent = new Intent(action);

		if (UUID_SERIAL_TRANSFER.equals(characteristic.getUuid())) {
			final byte[] data = characteristic.getValue();

			if (data != null && data.length > 0) {
				intent.putExtra(EXTRA_DATA, data);
			}
		} else {
			// For all other profiles, writes the data formatted in HEX.
			final byte[] data = characteristic.getValue();
			if (data != null && data.length > 0) {
				final StringBuilder stringBuilder = new StringBuilder(
						data.length);
				for (byte byteChar : data)
					stringBuilder.append(String.format("%02X ", byteChar));
				intent.putExtra(EXTRA_DATA, new String(data) /* + "\n" */
						+ stringBuilder.toString());
			}
		}
		sendBroadcast(intent);
	}

	public class LocalBinder extends Binder {
		public BluetoothLeService getService() {
			return BluetoothLeService.this;
		}
	}

	@Override
	public IBinder onBind(Intent intent) {
		return mBinder;
	}

	@Override
	public boolean onUnbind(Intent intent) {
		close();
		return super.onUnbind(intent);
	}

	private final IBinder mBinder = new LocalBinder();

	/**
	 * Initializes a reference to the local Bluetooth adapter.
	 * 
	 * @return Return true if the initialization is successful.
	 */
	public boolean initialize() {
		// For API level 18 and above, get a reference to BluetoothAdapter
		// through
		// BluetoothManager.
		if (mBluetoothManager == null) {
			mBluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
			if (mBluetoothManager == null) {
				Log.e(TAG, "Unable to initialize BluetoothManager.");
				return false;
			}
		}

		mBluetoothAdapter = mBluetoothManager.getAdapter();
		if (mBluetoothAdapter == null) {
			Log.e(TAG, "Unable to obtain a BluetoothAdapter.");
			return false;
		}

		return true;
	}

	/**
	 * Connects to the GATT server hosted on the Bluetooth LE device.
	 * 
	 * @param address
	 *            The device address of the destination device.
	 * 
	 * @return Return true if the connection is initiated successfully. The
	 *         connection result is reported asynchronously through the
	 *         {@code BluetoothGattCallback#onConnectionStateChange(android.bluetooth.BluetoothGatt, int, int)}
	 *         callback.
	 */
	public boolean connect(final String address) {
		if (mBluetoothAdapter == null || address == null) {
			Log.w(TAG,
					"BluetoothAdapter not initialized or unspecified address.");
			return false;
		}

		// Previously connected device. Try to reconnect.
		if (mBluetoothDeviceAddress != null
				&& address.equals(mBluetoothDeviceAddress)
				&& mBluetoothGatt != null) {
			Log.d(TAG,
					"Trying to use an existing mBluetoothGatt for connection.");
			if (mBluetoothGatt.connect()) {
				mConnectionState = STATE_CONNECTING;
				return true;
			} else {
				return false;
			}
		}

		final BluetoothDevice device = mBluetoothAdapter
				.getRemoteDevice(address);
		if (device == null) {
			Log.w(TAG, "Device not found.  Unable to connect.");
			return false;
		}
		// We want to directly connect to the device, so we are setting the
		// autoConnect
		// parameter to false.
		mBluetoothGatt = device.connectGatt(this, false, mGattCallback);
		Log.d(TAG, "Trying to create a new connection.");
		mBluetoothDeviceAddress = address;
		mConnectionState = STATE_CONNECTING;
		return true;
	}

	/**
	 * Disconnects an existing connection or cancel a pending connection. The
	 * disconnection result is reported asynchronously through the
	 * {@code BluetoothGattCallback#onConnectionStateChange(android.bluetooth.BluetoothGatt, int, int)}
	 * callback.
	 */
	public void disconnect() {
		if (mBluetoothAdapter == null || mBluetoothGatt == null) {
			Log.w(TAG, "BluetoothAdapter not initialized");
			return;
		}
		mBluetoothGatt.disconnect();
	}

	/**
	 * After using a given BLE device, the app must call this method to ensure
	 * resources are released properly.
	 */
	public void close() {
		if (mBluetoothGatt == null) {
			return;
		}
		mBluetoothGatt.close();
		mBluetoothGatt = null;
	}

	/**
	 * Request a read on a given {@code BluetoothGattCharacteristic}. The read
	 * result is reported asynchronously through the
	 * {@code BluetoothGattCallback#onCharacteristicRead(android.bluetooth.BluetoothGatt, android.bluetooth.BluetoothGattCharacteristic, int)}
	 * callback.
	 * 
	 * @param characteristic
	 *            The characteristic to read from.
	 */
	public void readCharacteristic(BluetoothGattCharacteristic characteristic) {
		if (mBluetoothAdapter == null || mBluetoothGatt == null) {
			Log.w(TAG, "BluetoothAdapter not initialized");
			return;
		}
		mBluetoothGatt.readCharacteristic(characteristic);
	}

	public void writeCharacteristic(BluetoothGattCharacteristic characteristic) {
		if (mBluetoothAdapter == null || mBluetoothGatt == null) {
			Log.w(TAG, "BluetoothAdapter not initialized");
			return;
		}
		while (!writeDone) {
			try {
				Thread.sleep(20);
			} catch (InterruptedException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
		}
		writeDone = false;
		mBluetoothGatt.writeCharacteristic(characteristic);
	}

	/**
	 * Enables or disables notification on a give characteristic.
	 * 
	 * @param characteristic
	 *            Characteristic to act on.
	 * @param enabled
	 *            If true, enable notification. False otherwise.
	 */
	public void setCharacteristicNotification(
			BluetoothGattCharacteristic characteristic, boolean enabled) {
		if (mBluetoothAdapter == null || mBluetoothGatt == null) {
			Log.w(TAG, "BluetoothAdapter not initialized");
			return;
		}
		mBluetoothGatt.setCharacteristicNotification(characteristic, enabled);

		// This is specific to Heart Rate Measurement.
		if (UUID_SERIAL_TRANSFER.equals(characteristic.getUuid())) {
			BluetoothGattDescriptor descriptor = characteristic
					.getDescriptor(UUID
							.fromString(SampleGattAttributes.CLIENT_CHARACTERISTIC_CONFIG));
			descriptor
					.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
			mBluetoothGatt.writeDescriptor(descriptor);
		}
	}

	/**
	 * Retrieves a list of supported GATT services on the connected device. This
	 * should be invoked only after {@code BluetoothGatt#discoverServices()}
	 * completes successfully.
	 * 
	 * @return A {@code List} of supported services.
	 */
	public List<BluetoothGattService> getSupportedGattServices() {
		if (mBluetoothGatt == null)
			return null;

		return mBluetoothGatt.getServices();
	}

	private ArrayList<ArrayList<BluetoothGattCharacteristic>> mGattCharacteristics = new ArrayList<ArrayList<BluetoothGattCharacteristic>>();

	public BluetoothGattCharacteristic transferChar;

	private final String LIST_NAME = "NAME";
	private final String LIST_UUID = "UUID";

	private void discoverGattServices(List<BluetoothGattService> gattServices) {
		if (gattServices == null)
			return;
		String uuid = null;
		String unknownServiceString = "Unknow Service";
		String unknownCharaString = "Unknow Charatic";
		ArrayList<HashMap<String, String>> gattServiceData = new ArrayList<HashMap<String, String>>();
		ArrayList<ArrayList<HashMap<String, String>>> gattCharacteristicData = new ArrayList<ArrayList<HashMap<String, String>>>();
		mGattCharacteristics = new ArrayList<ArrayList<BluetoothGattCharacteristic>>();

		for (BluetoothGattService gattService : gattServices) {
			HashMap<String, String> currentServiceData = new HashMap<String, String>();
			uuid = gattService.getUuid().toString();
			currentServiceData.put(LIST_NAME,
					SampleGattAttributes.lookup(uuid, unknownServiceString));
			currentServiceData.put(LIST_UUID, uuid);
			gattServiceData.add(currentServiceData);

			ArrayList<HashMap<String, String>> gattCharacteristicGroupData = new ArrayList<HashMap<String, String>>();
			List<BluetoothGattCharacteristic> gattCharacteristics = gattService
					.getCharacteristics();
			ArrayList<BluetoothGattCharacteristic> charas = new ArrayList<BluetoothGattCharacteristic>();

			// Loops through available Characteristics.
			for (BluetoothGattCharacteristic gattCharacteristic : gattCharacteristics) {
				charas.add(gattCharacteristic);
				HashMap<String, String> currentCharaData = new HashMap<String, String>();
				uuid = gattCharacteristic.getUuid().toString();
				if (uuid.equals(SampleGattAttributes.SERIAL_TRANSFER)) {
					transferChar = gattCharacteristic;
					setCharacteristicNotification(transferChar, true);
					broadcastUpdate(ACTION_DEVICE_FIND);
				}
				currentCharaData.put(LIST_NAME,
						SampleGattAttributes.lookup(uuid, unknownCharaString));
				currentCharaData.put(LIST_UUID, uuid);
				gattCharacteristicGroupData.add(currentCharaData);
			}
			mGattCharacteristics.add(charas);
			gattCharacteristicData.add(gattCharacteristicGroupData);
		}
	}

	public void send(String msg) {
		if (transferChar != null) {
			transferChar.setValue(msg);
			writeCharacteristic(transferChar);
		}
	}

	public void send(byte[] msg) {
		if (transferChar != null) {
			transferChar.setValue(msg);
			writeCharacteristic(transferChar);
		}
	}

}
